Lithographic dampening mechanism.



C. HENDERSON.

LITHOGRAPHIC DAMPENING MECHANISM.

APPLICATION men APR. 10. 1916.

Pat'ented July 3, 191.7.

CARL HENDERSON, OF OAK PARK, ILLINOIS. ASSIGNOR T0 MIEHLE PRINTING IRESS d8 MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LITHOGRAIHIC DAMPENING MECHANISM.

earner.

To all whom it may concern:

Be it known that I, CARL HENDERSON, a citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Lithographic Dampening Mechanism, of which the following is a specification.

The object of the invention is the arrangement and operation of the rolls for transfer- .rin water from the dam enin trou h to b h b the plate cylinder of a lithographic press in such manner as to most efficiently and uniformly dampen the same in use.

Heretofore it has been usual to employ two plate cylinder dampening rolls, a rider roll in contact with the two plate cylinder rolls, a dispensing roll running in the water in the trough, and a ductor roll oscillating between the dispensing roll and the rider roll. This arrangement is subject to the objection that that one of the plate-dampening rolls with which the" dampened area of the rotating rider roll first contacts will take up substantially all the moisture therefrom leaving practically none to be transmitted to the other plate-dampening roll;

this objection being accentuatedby the fact that in operation the freshly inked surface of the plate cylinder will first pass under the comparatively dry plate-dampening roll.

As distinguished from this customary arrangement, the present invention contemplates the substitution of a second distributing ductor roll, contacting alternately with each of the two plate cylinder dampening rolls, for the usual rider roll which remained always in contact with both, the water being transmitted from the dispensing roll by the usual transferring ductor to the distributing ductor, and the latter transmitting it to one of the dampening rolls, and then after receiving a second supply from the transfer ductor transmitting it in turn to the second dampening roll, whereby the two dampening rolls receive in alternation an equal amount of moisture for application to the printing plate cylinder.

In order that the invention may be readily understood a preferred embodiment of the same is set forth in the following detailed description and in the accompanying drawing wherein is shown in diagrammatic form "the arrangement of the dampening rolls according to the present invention, the said Specification of Letters Patent.

Patented-July 3, llQiW.

Application filed April 10, 1916. Serial No. 90,193.

illustration serving as a basis for the detailed description. Obviously the invention is susceptible of embodiment in other and varied constructional forms, wherefore the drawlng and description are to be taken in an illustrative and not in an'unnecessarily limiting sense. Y

v In the drawing the dampening trough is indicated at 11, the dispensing roll at 12, the usual transferring ductor at 13 carried by the arm 14 pivoted to the machine frame, the distributing ductor at 15 carried by the arm 16, likewise pivoted to the machine frame, and the two dampening rolls at 17 and 18 respectively, the plate cylinder being indicated at 19. These various rolls are driven in any Well known mechanical way and, as the driving mechanism forms. no part of the present invention, it is not herein shown and described in detail. As is usual, the dispensing roll 12 has a metallic surface while the transfer ductor 13 and the dampening rolls 15 and 18 have an absorbent surface. The distributing ductor 15 has a metallic surface as is usually the case with the ordinary rider roll.

It will be readily understood that the distributing ductor 15 is arranged to oscillate between the two dampening rolls 17 and 18, whilethe transfer ductor 13 oscillates between the dispensing roll 12 and the distributing ductor 15 in'theintermediate position of the latter shown in the drawing.

In operation, a supply of moisture is taken from the dispensing roll 12 by the transfer ductor 13 which swings into contact with the distributing ductor 15; thereupon the ductor 15 swings into contact with the dampening roll 17, and at the same time the ductor 13 swings back to the dispensing roll 12 for a fresh supply of moisture. The ductor 15 having moved back to its intermediate position it receives a second supply of moisture from the ductor 13 which it in turn transmits to the dampening roll 18 while the ductor 13 is returning to the dispensing roll for a fresh supply. Thus the amount of moisture is distributed equally to the dampening rolls 17 and 18 and each, therefore, acts in equal degree upon the plate cylinder 19 in moistening the same.

I claim:

1. In lithographic dampening mechanism, the combination with the printing plate cylinder, of a plurality of plate-dampening rolls in constant contact with the plate cylinder, a water trough, and means to distribute the water from the trough to'the dampening rolls in uinform degree.

2. In lithographic dampening mechanism, the combination with the printing plate cylinder, of a plurality of plate-dampening rolls in constant contact with the plate cylinder, a water supply, and a ductor roll arranged to receive moisture from the water supply and to contact in succession with the dampening rolls, whereby to distribute the moisture to the dampening rolls in equal degree.

3. In lithographic dampening mechanism, the combination with the plate cylinder, of a pair of plate-dampening rolls in constant contact with the plate cylinder, a water supply, a ductor roll arranged to contact alternately with each of the dampening rolls, and means to transfer water from the supply to the ductor roll, whereby to moisten the dampening rolls in equal degree.

4. In lithographic dampening mechanism the combination with the plate cylinder, 0 a pair of plate'dampening rolls in constant contact with the plate cylinder, a water supply, a ductor roll arranged to contact alternately with each of the dampening rolls, and means to transfer water from the supply to the ductor roll between each contact of said ductor roll with a dampening roll, whereby to moisten the two dampening rolls in equal degree.

5. In lithographic dampening mechanism, the combination with the plate cylinder, of a pair of plate dampening rolls, a water supply, a transferring ductor arranged to receive moisture from the supply, a distributing ductor arranged to receive the moisture from the transfer ductor, the transfer ductor mounted to contact with the distributing ductor and to receive its own supply of moisture in alternation, and the distributing ductor to contact alternately with the plate dampening rolls and intermediately with the transfer ductor, whereby to moisten each of the dampening rolls in equaldegree.

6. In lithographic dampening mechanism, the combination with the plate cylinder, of a pair of plate dampening .rolls, a water supply, a water dispensing roll, a transferring ductor, adistributing ductor, the transfer ductor mounted to swing into contact alternately with the dispensing roll and the distributing ductor and the latter mounted to swing into contact alternately with the two plate dampening rolls and .to intermediately contactwith the transfer ductor, whereby to moisten the two dampening rolls in equal degree.

In witness whereof I have hereunto signed my name in the presence of two subscribing CARL HENDERSON.

witnesses.

Witnesses C. I-IIoKMAN. C. D. GIBBS. 

